function line = LLDescriptor(img, bNormalization)
%
%        imgOut = LLDescriptor(img, bNormalization)
%
%        This function creates a descriptor for an environment map in
%        logituted latitude (LL) coordinates. The descriptor can be used
%        for aligning environment maps.
%
%        Input:
%           -img: an environment map encoded with LL encoding
%           -bNormalization: normalization flag
%        Output:
%           -line: the descriptor line for an environment map
%
%     Copyright (C) 2012-15  Francesco Banterle
% 
%     This program is free software: you can redistribute it and/or modify
%     it under the terms of the GNU General Public License as published by
%     the Free Software Foundation, either version 3 of the License, or
%     (at your option) any later version.
% 
%     This program is distributed in the hope that it will be useful,
%     but WITHOUT ANY WARRANTY; without even the implied warranty of
%     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%     GNU General Public License for more details.
% 
%     You should have received a copy of the GNU General Public License
%     along with this program.  If not, see <http://www.gnu.org/licenses/>.
%

if(~exist('bNormalization', 'var'))
    bNormalization = 0;
end

line = sum(lum(img));

if(bNormalization)
    line = line / max(line);
end

end